Multi-pane window units are well known. Multi-pane window units include insulating glass units which include at least two window panes separated by a spacer which extends around the periphery of the separated window panes. The spacer or profile is typically a tubular, substantially rectangular shaped, hollow member. The spacer is typically formed from thin sheet metal, and may be formed so as to have ribs and/or channels and fins imparted to increase the structural strength of the thin walled spacer.
Insulating glass units may be formed by combining a substantially linear, tubular, metallic spacer and two glass window panes. The insulating glass units are formed in many shapes, including rectangular, triangular, circular, arcuate, and combinations of these shapes. Rectangular shaped insulating glass units are the most common. In one method, the spacer is formed from a sheet metal strip into a substantially rectangular cross-sectional shape having a length approximately equal to the total perimeter of the glass panes to be joined. For use in a rectangular shaped insulating glass unit, the spacer can be run through a bending unit to form four substantially rectangular corners. In an illustrative example of one method, a metallic spacer member begins along the top, near the upper left corner of the insulating glass unit extends across to the upper right corner, bends to extend downward to the lower right corner, bends to extend leftward to the lower left corner, bends to extend upward to the upper left corner, and bends to extend rightward to meet the opposite end of the spacer at the top, left region of the insulating glass unit. The opposing ends of the spacer are typically joined together to form a sealed, mechanically sound joint.
A gap is inherently formed between the two abutting spacer ends. This gap may lead to unwanted gas exchange between the between pane space and the atmosphere. One path for this exchange is from the gap alongside a connector (if present), between the connector and the enclosing spacer wall, continuing into the interior of the spacer past the connector, then into the insulating gas space between the panes through the breather holes in the spacer wall. This gas exchange path is preferably very tight and long.
One connector joint is formed by inserting a mechanical connector between the abutting spacer ends, and wrapping the outward and sideward faces of the spacer with a metallic tape or metallic cap using a dedicated machine. The side edges of the spacer nearest the inward face of the spacer can be joined with sealant to the glass panes disposed on either side of the spacers. The dedicated machine can be difficult to operate and maintain.
In one method, the two spacer ends are held together in a jig, and a sealant material is injected into the spacer near the joined ends. The sealant may flow into both open spacer ends, and be allowed to cure. The resulting joint integrity may be limited by the structural strength of the sealant after curing. This method also may require a long curing time, as the facing ends of the opposite spacer may have little structural integrity until the sealant is cured.
In another method, a mechanical key or connector is inserted into both ends of the spacer. In one such method, sealant is applied into or onto the outward facing surface of the connector key and the connector key opposite arms inserted into the facing spacer openings. Each of the facing spacer members may then be crimped, thereby forcing the sealant to run from the opposite spacer openings into a central region between the two opposite spacer members. In this method, the sealant may reside primarily in the outside surface portion of the joined spacers and the joined spacers may suffer aesthetically from having been crimped. The crimping may, in some methods, also reduce the structural integrity of the joined members.
What would be desirable is an improved mechanical key or connector for joining multi-pane window spacer ends. What would be advantageous are improved methods for joining together window spacer members.